Moored buoys are well known in the prior art for use in various purposes, including marking navigational hazards, aids to navigation channels, etc. A moored surface buoy must have a relatively high net buoyancy to limit overtopping in higher sea states. In the case of high surface current, the high net buoyancy is needed to prevent the buoy from being drug under by the tension in the mooring.
In some instances, buoys are deployed from a ship. In other instances, it may be desired to deploy a buoy from a stowage configuration that is already underwater. Reasons for such stowage can include preventing (or at least slowing) the growth of marine growths such as kelp on the outer hull of the buoy. For these cases, a buoy could be required to ascend a water column for deployment, and descend in the water column during retraction and re-stowage. During the retraction phase, a large relative force may be required to bring it back down to the stowage structure. By adding a pressure sensitive variable buoyancy, the buoy can have the advantage of relatively large excess buoyancy at the surface, while having a significantly decreased net buoyancy at depth; thus, saving energy during descent.
In view of the above, it is an object of the present invention to provide a variable buoyancy buoy having variable buoyancy, which can be protected inside a flooded area inside the main floatation portion of the buoy. Another object of the present invention is to provide a variable buoyancy buoy that inhibits formation of marine growth on the buoy and maintains a kelp shedding aspect for the buoy. Still another object of the present invention is to provide a variable buoyancy buoy that decrease in buoyancy with increase depth in the water. Yet another object of the present invention is to provide a variable buoyancy buoy that can require decreased power to retract the buoy when the buoy is stowed underwater. Another objective of the present invention is to provide a variable buoyancy buoy, which is easy to manufacture and use in a cost-effective manner.